China Unicom Ltd., the country's No. 2 mobile phone carrier, said Tuesday it has started testing a music download service offering subscribers songs from 23 record companies.

The move comes as music and telecommunications firms try to raise sales and curb piracy by providing convenient channels for consumers to buy legitimate music.

The trial service, called Xuan Qu in Chinese, allows subscribers to download songs to mobile phones for 3-5 Chinese yuan ($0.39-$0.66) each, said Tong Xiaoyu, China Unicom's GM for value-added services.

The service protects copyrights by preventing users from transferring the music to other mobile phones or computers, he said.

Record companies offering songs on the download service include EMI Group PLC, Sony BMG Music Entertainment, Warner Music Group Corp. and Universal Music Group, Tong said.

The trial started June 28 and will continue until the end of September. China Unicom will then review and refine the service for a second trial, which will likely start in October, said Tong.

China's telecom firms -- like telecom companies elsewhere in the world -- have been exploring ways to increase revenue from data services, such as music downloads or mobile phone Internet access, as charges for phone calls have fallen amid intense competition among themselves and from less expensive alternatives, such as Ebay Inc.'s Internet-based calling software Skype.

China's larger mobile carrier, China Mobile Ltd., bought a 19.9% stake in Phoenix Satellite Television Holdings Ltd. last year as part of its expansion in value-added services.